In diagnosing and treating heart diseases caused by occlusion of the coronary arteries, a physician may perform various tests and non-surgical procedures in which a catheter is guided through an artery in the arm or leg and into the selected coronary artery of the heart. Once in place, the catheter is then used for performing diagnostic tests such as a coronary angiography in which a radioimaging material is injected to visualize the arteries, or therapeutic interventions such as a coronary angioplasty, stenting, or atherectomy.
In a femoral catheterization procedure, the catheter is introduced into the aorta via the femoral artery in the leg. A drawback of this procedure is that, after it is completed, the patient must remain flat and immobilized with pressure applied to the wound for an extended period of time of about 4-6 hours to ensure that the bleeding stopped.
With a brachial catheterization, the catheter is introduced via the brachial artery in the arm. With this procedure, the patient can be up and walking within a shorter rest period of only about 1-2 hours. However, the deep location of the artery leads to increased bleeding complications, and thrombosis of the artery can occur. Another disadvantage is that a catheter inserted into the brachial artery undesirably cuts off blood flow into the lower arm, wrist and hand. In addition, the shapes of the distal end of coronary catheters that have been described for insertion using a brachial artery approach, such as those in U.S. Pat. No. 5,299,574 (Bower) and U.S. Pat. No. 5,471,986 (Ishimura), could be improved to more securely maintain the tip of the catheter engaged within the artery and prevent it from backing out of the coronary ostium when angioplasty equipment is advanced into the artery.
A relatively new technique is a transradial approach in which the catheter is introduced into the aorta via the radial artery in the wrist. The radial artery and the ulnar artery are two small arteries in the wrist that communicate through the palmar arch. Advantageously, insertion of a catheter into the radial artery does not cut off blood flow into the lower arm or hand because the blood can continue to flow through the ulnar artery and palmar arch. This approach also requires a relatively short recovery time of about 10-15 minutes to ensure that bleeding has stopped from the surgical wound. Thus, an advantage of the use of a transradial approach for diagnostic catheterization and intervention over femoral or brachial coronary intervention approaches is the early discharge of the patient into outpatient care, and the cost reductions associated with the early discharge and increased availability of recovery beds. In addition, transradial intervention procedures can be performed in a less complicated setting than is required in a femoral or brachial procedure. However, since this approach for coronary angiography was first described in 1989 by Dr. Lucien Campeau (Cathet. Cardiovasc. Diagn. 16:3-7 (1989)), it has gained acceptance in Europe, but only minimal acceptance in the United States. A barrier to the use of this technique is that existing catheters are not designed for optimal use from the radial artery. Current catheters require excessive manipulation and become easily dislodged during examination or treatment.
Therefore, an object of the invention is to provide a catheter for use in coronary diagnosis and/or treatment that is specifically configured for insertion into a coronary artery via a transradial approach. Another object is to provide a right and left radial catheter having a shape such that, when a force is applied that tends to displace the catheter tip out of the ostium of the artery, such as when advancing equipment and/or injecting a dye through the catheter into the artery, the tip of the catheter will not become dislodged and will remain securely seated in the ostium of the artery until completion of the procedure. Yet another object is to provide catheters that require minimal manipulation to engage the coronary ostium, thereby facilitating the ease of the procedure.